Review of a published article (Kakitsuba N. Comfortable Indoor Lighting Conditions Evaluated from Psychological and Physiological Responses.)

This note is a critical review of the spatial brightness experiment reported by Kakitsuba [Kakitsuba 2015]. There are several reasons why I think the study is flawed and therefore that the results should not be considered credible. In particular, the results can largely be explained by a stimulus range bias, the ‘boundary’ illuminances tending to lie near the centre of each range of illuminances reported. Therefore the results are a product of the illuminance ranges chosen by the experimenter and do not indicate observers’ preferences for light level.